8.31 Marijuana and work. How does smoking marijuana affect willingness to work? Canadian researchers persuaded young adult men who used marijuana to live for 98 days in a "planned environment." One group smoked two potent marijuana cigarettes every evening. The other group smoked two weak marijuana cigarettes. All subjects could buy more cigarettes but were given strong or weak cigarettes depending on their group. Did the weak and strong groups differ in work output?'^

(a) Outline the design of this experiment.

(b) Here are the names of the 20 subjects. Use software or Ta ble B at line 131 to carry out the randomization your design requires.

Abate Dubois Gutierrez Lucero Rosen Afifi Engel Huang McNeill Thompson Brown Fluharty Iselin Morse Travers Cheng Gerson Kaplan Quinones Ullmann